import { describe, expect, test } from "bun:test";
import type { ImageDocument } from "@core/document";
import type { Layer } from "@core/layer";
import { createDocumentReadIndex, forEachLayerBackToFront, resolveIndexedLayerBounds } from "./document-indexes";

const document: ImageDocument = {
  id: "d1",
  name: "Indexed Document",
  version: 1,
  assets: [
    { id: "asset-target", name: "Target", mimeType: "image/png", source: "asset://target", intrinsicSize: { w: 100, h: 50 } },
    { id: "asset-mask", name: "Mask", mimeType: "image/png", source: "asset://mask", intrinsicSize: { w: 100, h: 50 } },
    { id: "asset-nested", name: "Nested", mimeType: "image/png", source: "asset://nested", intrinsicSize: { w: 20, h: 10 } },
  ],
  artboards: [
    {
      id: "a1",
      name: "Artboard",
      bounds: { x: 0, y: 0, w: 400, h: 300 },
      backgroundColor: "transparent",
      visible: true,
      locked: false,
      layers: [
        raster("mask", "Mask", "asset-mask"),
        {
          ...raster("target", "Target", "asset-target", { x: 10, y: 20 }, { x: 0.5, y: 0.5 }),
          layerMask: { kind: "raster", maskLayerId: "mask", enabled: true, inverted: false },
        },
        group("group", "Group", [
          raster("nested-mask", "Nested Mask", "asset-mask"),
          { ...raster("nested-target", "Nested Target", "asset-nested", { x: 80, y: 10 }, { x: 2, y: 3 }), clippingMask: { maskLayerId: "nested-mask" } },
        ]),
      ],
    },
  ],
};

describe("document read indexes", () => {
  test("indexes assets, layers, layer info, masks, and display counts", () => {
    const index = createDocumentReadIndex(document);

    expect(index.assetById.get("asset-target")).toBe(document.assets[0]);
    expect(index.layerById.get("nested-target")?.name).toBe("Nested Target");
    expect(index.layerInfoById.get("target")).toMatchObject({ artboardId: "a1", index: 1 });
    expect(index.layerInfoById.get("nested-target")).toMatchObject({ artboardId: "a1", parentGroupId: "group", index: 1 });
    expect(index.maskLayerIds).toEqual(new Set(["mask", "nested-mask"]));
    expect(index.maskLayerIdsByArtboardId.get("a1")).toEqual(new Set(["mask", "nested-mask"]));
    expect(index.maskLayerIdsByLayerList.get(document.artboards[0]!.layers)).toEqual(new Set(["mask", "nested-mask"]));
    expect(index.maskLayerIdsByLayerList.get(groupLayer(document, "group").children)).toEqual(new Set(["nested-mask"]));
    expect(index.displayLayerCountByArtboardId.get("a1")).toBe(3);
  });

  test("resolves layer bounds from indexed assets without scanning the document", () => {
    const index = createDocumentReadIndex(document);

    expect(resolveIndexedLayerBounds(index, "target")).toEqual({ x: 10, y: 20, w: 50, h: 25 });
    expect(resolveIndexedLayerBounds(index, "group")).toEqual({ x: 0, y: 0, w: 120, h: 50 });
    expect(resolveIndexedLayerBounds(index, raster("missing", "Missing", "missing-asset"))).toBeUndefined();
  });

  test("visits layers back to front without mutating source order", () => {
    const layers = document.artboards[0]!.layers;
    const visited: string[] = [];

    forEachLayerBackToFront(layers, (layer) => visited.push(layer.id));

    expect(visited).toEqual(["group", "target", "mask"]);
    expect(layers.map((layer) => layer.id)).toEqual(["mask", "target", "group"]);
  });
});

function raster(
  id: string,
  name: string,
  assetId: string,
  position = { x: 0, y: 0 },
  scale = { x: 1, y: 1 },
): Extract<Layer, { type: "raster" }> {
  return {
    id,
    type: "raster",
    name,
    visible: true,
    locked: false,
    opacity: 1,
    assetId,
    transform: { position, scale, rotation: 0 },
  };
}

function group(id: string, name: string, children: Layer[]): Extract<Layer, { type: "group" }> {
  return {
    id,
    type: "group",
    name,
    visible: true,
    locked: false,
    opacity: 1,
    transform: { position: { x: 0, y: 0 }, scale: { x: 1, y: 1 }, rotation: 0 },
    children,
  };
}

function groupLayer(document: ImageDocument, id: string): Extract<Layer, { type: "group" }> {
  const layer = document.artboards[0]!.layers.find((candidate) => candidate.id === id);
  if (!layer || layer.type !== "group") throw new Error(`Missing group ${id}`);
  return layer;
}